white



(No Model.)

G. H. WHITE. CARBON BRUSH HOLDER,

NO. 549,663. Patented N0v.,12,18 95.

y UNITED STATES i PATENT OFFICE.

GEORGEH. IVIIITE, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE SIEMENS t IIALSKE ELECTRIC COMPANY OF AMERICA, OF SAME PLACE.

CARBON-BRUSH HOLDER.

SPECIFICATION forming part of Iietters Patent Nol 549,663, dated November 12, 1895.

Serial No. 558,249. (No model.)

To all whom, it ntay concern.-

Be it known that I, GEORGE H. IVHITE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Carb on-Brush Holders, of which the following is a specification.

My invention rela-tes to a carbon-brush holder, my obj ect being to construct a brush holder in which the carbon-brush may be firmly maintained in electrical contact with the metallic port-ions of the holder, while the carbon is mounted so that it may have a freedom of motion relatively to the fixed holder to permit the carbon to readily adapt itself to the commutator. The carbon block or brush is mounted in a clamp or housing', in which it is securely fastened, the face of the brush being maintained in contact with a plane surface of the housing, whereby the resistance between the brush and the metallic portions of the holder is reduced to a minimum. The clamp in which the brush is mounted has a freedom of movement relatively to the stationarily-mounted portion of the holder such that the clamp may move relatively to the holder in a longitudinal direction or may be rotated either forward or backward in the plane of rotation of the coinmutator. Springs are provided for yieldingly maintaining the clamp in a definite position relatively to t-he holder, so that the brush is maintained upon the eommutator due to the tension of the springs and is fed forward by said springs as the brush wears away. By mounting the carbon block fixedly within a carbon-clamp the necessity of coating the carbon with copper or other conducting inaterial is avoided. Between the clamp and the holder is provided a iexible conductor, which insures a good electrical connection between the stationary and movable parts of the holder. Upon the clamp er housing is provided an adjusting-screw, by means of which the carbon-brush may be moved within the clamp as may be desired. Initially the pressure with which the brush is pressed against the commutator may be determined by adjusting the position of the stationary holder upon its supporting-rod, while during the operation of the machine the tension may be adjusted from time to time by means of the screw, which moves the carbon block within its holder. Two sets of springs are provided, one of which opposes the rotation of the clamp relatively tothe holder in one direction, while the other set opposes the rotation in the opposite direction. I'Vhen the armature rotates in one direction, one set of springs is made of increased tension, while when it rotates in the opposite direction the other set of springs is made-of increased tension.

Referring to the accompanying drawings, Figure l is a view, partially in section, of the brush-holder of my invention. Fig. 2 is a similar View showing the carbon-clamp rotated in one direction. Fig. 3 is a similar View showing the clamp rotated in the opposite direction. Fig. 4 is a front view of the carbon-holder.

Like letters refer to like parts in the several figures.

Upon the supporting rod or arm a is mounted the holder b, a screw b being provided whereby the holder b may be clamped upon the rod a or may be released to permit the angular adjustment of the holder upon the rod a. The holder b is provided with a surface-plate b2, against which rests the carbon clamp or housing, which is provided with aplate c, adapted to rest against the surface-plate h2. IVithin the clamp is provided the carbon or brush CZ, the face of which rests against the plate c to insure firm electrical contact between the brush d and the clamp. A screw e, provided with a thumbpiece c, is adapted to engage a tapped hole in the housing c', secured to the plate c, and engages by its end a clamping-plate e2, which when the screw is turned is pressed against the carbon CZ to maintain it more intimately in contact with plate c. At the upper end of the clamp is provided an adjustingscrew f, provided with a thumb-piece f, the 95 end of the screw resting upon the top of the carbon block d, whereby when the screw c is turned to unclamp the carbon the carbon may be moved downward relatively to the plate c through the agency of the screw f. 10o Upon the holder b is carried a rod b3, to which are secured the ends of the springs g g,

the opposite ends of the springs being connected with posts g g', carried upon the rear of plate c. Likewise the spring or springs 7L extend between the rod b3 and the post g2, carried upon the rear of the plate c. The springs thus co-operate to maintain the clamp in engagement with the surface-plate b2, but permit the movement of the clamp relatively to the surface-plate. The clamp may rotate about the lower end of the surface-plate b2, as illustrated in Fig. 2, or it may rotate about the upper end of the surface-plate, as illustrated in Fig. 3, the coiled springs serving to move the clamp into position to return the clamp to its original position against the surfaceplate b2 when the force tending to rotate the clamp is removed. The brush may be employed with a coinmutator rotating in either direction. lf, as seen in Fig. 3, the rotation be clockwise, the spring 7i should be made of increased tension to counteract the pull due to the friction of the commutator upon the brush. If the rotation be in the opposite direction, the springs g should be made of increased tension. By thus inserting springs of a greater or less tension the brush may be adapted for rotation in either direction. NVhen the clamp is rotated relatively to the holder, as illustrated in Figs. 2 and 3, the clamp makes contact with the holder only along a single line, and it is therefore desirable to provide a permanent electrical connection of considerable cross section between the clamp and the holder. For this purpose a flat piece of metal k is secured by one end to the holder l) by means of screws 7s and at the opposite end to the clamp by means of screws k2, the intermediate portion being bent or convoluted to permit the clamp to move freely relatively to the holder.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. In a carbon brush holder, the combination with a clamp having a flat surface against which the carbon brush or block is adapted to be fixedly clamped, of aholder upon which said clamp is mounted, and a resilient connection between said clamp and said holder permitting the longitudinalv movement of said clamp and also a rocking movement forward and backward in the plane of the commutator; substantially as described.

2. The combination with a holder having a surface plate7 of a clamp or housing containing the carbon brush an d resting against said surface plate, means being provided for permitting the rotation of said clamp about the upper or the lower end of said surface plate and for permitting the longitudinal movement of the clamp relatively to the surface plate; substantailly as described.

3. The combination with the holder l) carrying the surface plate b2, of the clamp comprising the plate c adapted to rest against the surface plate b2, the carbon brush being normally fixedly clamped against said plate c, the bar b3 mounted upon the holder, and springs g and 7L between said bar b3 and the posts f/ g2 carried upon the plate c; substantially as described.

4. The combination with a holder,of a clamp adapted to rotate in one direction about the upper end of said holder, and in the opposite direction about the lower end of said holder, and springs for resiliently opposing the rotation in either direction, whereby the brush holder may be adapted to an armature rotating in either direction by increasing the tension of the spring opposing the force due to the friction of the brush upon the commutator; substantially as described.

5. The combination with the holder b, previded with surface plate 192, of the clamp, comprising the plate c, housing c', clamping plate c2 and clamping screw c, the adjusting screw f, rod Irs mounted upon the holder, springs g and h situated between said rod '3 and the posts g and g2 provided upon the plate c, and the convoluted or bent flat conductor 7c electrically connecting the clamp with the holder; substantially as described.

In testimony whereof I affix my signature in the presence of two witnesses.

GEORGE H. VHITE.

Vitnesses:

CHARLES A. BROWN, JOHN W. SINCLAIR. 

